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Genetically-based olfactory signatures persist despite dietary variation.

Kwak J, Willse A, Matsumura K, Curran Opiekun M, Yi W, Preti G, Yamazaki K, Beauchamp GK - PLoS ONE (2008)

Bottom Line: Chemical analyses of urinary volatile organic compounds (VOCs) extracted by solid phase microextraction (SPME) and analyzed by gas chromatography/mass spectrometry (GC/MS) are consistent with this inference.Although diet influenced VOC variation more than MHC, with algorithmic training (supervised classification) MHC types could be accurately discriminated across different diets.Thus, although there are clear diet effects on urinary volatile profiles, they do not obscure MHC effects.

View Article: PubMed Central - PubMed

Affiliation: Monell Chemical Senses Center, Philadelphia, Pennsylvania, USA.

ABSTRACT
Individual mice have a unique odor, or odortype, that facilitates individual recognition. Odortypes, like other phenotypes, can be influenced by genetic and environmental variation. The genetic influence derives in part from genes of the major histocompatibility complex (MHC). A major environmental influence is diet, which could obscure the genetic contribution to odortype. Because odortype stability is a prerequisite for individual recognition under normal behavioral conditions, we investigated whether MHC-determined urinary odortypes of inbred mice can be identified in the face of large diet-induced variation. Mice trained to discriminate urines from panels of mice that differed both in diet and MHC type found the diet odor more salient in generalization trials. Nevertheless, when mice were trained to discriminate mice with only MHC differences (but on the same diet), they recognized the MHC difference when tested with urines from mice on a different diet. This indicates that MHC odor profiles remain despite large dietary variation. Chemical analyses of urinary volatile organic compounds (VOCs) extracted by solid phase microextraction (SPME) and analyzed by gas chromatography/mass spectrometry (GC/MS) are consistent with this inference. Although diet influenced VOC variation more than MHC, with algorithmic training (supervised classification) MHC types could be accurately discriminated across different diets. Thus, although there are clear diet effects on urinary volatile profiles, they do not obscure MHC effects.

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Typical total ion chromatograms from the urinary volatiles extracted from four mouse groups.One representative chromatogram each from B6 mice fed Diet L, B6 mice fed Diet S, B6-H2K mice fed Diet L and B6-H2K mice fed Diet S is shown here. Prominent compound peaks include 2-acetyl-1-pyrroline (11.99 min), beta-farnesene (19.00 min), alpha-farnesene (20.63 min), and the mouse pheromones 2,3-dehydro-exo-brevicomin (13.62 min) and 2-sec-butyl-4,5-dihydrothiazole (14.93 min).
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pone-0003591-g001: Typical total ion chromatograms from the urinary volatiles extracted from four mouse groups.One representative chromatogram each from B6 mice fed Diet L, B6 mice fed Diet S, B6-H2K mice fed Diet L and B6-H2K mice fed Diet S is shown here. Prominent compound peaks include 2-acetyl-1-pyrroline (11.99 min), beta-farnesene (19.00 min), alpha-farnesene (20.63 min), and the mouse pheromones 2,3-dehydro-exo-brevicomin (13.62 min) and 2-sec-butyl-4,5-dihydrothiazole (14.93 min).

Mentions: Figure 1 shows four typical total ion chromatograms (TICs) from analyses of urinary VOCs extracted by SPME from the four mouse groups (C57BL/6J (B6) Diet L, B6 Diet S, C57BL/6J-H2k (B6-H2k) Diet L, and B6-H2k Diet S). Statistical analysis of the GC/MS data collected from the 37 individual mice was performed to identify differentially-expressed compounds, many of which might co-elute with other peaks. Over 100 distinct chromatographic components were detected and we were able to identify 25 of them and another 24 compounds were tentatively identified, as seen in Table 3. Separate analyses were performed using the full profile of chromatographic components and the 49 identified components, with the same general conclusions. Unless otherwise stated, reported results are based on analysis of the 49 identified compounds so that conclusions could be attributed to known compounds, and to remove any concern that reported differences are due to instrumental artifacts or contamination. All compounds were present in each of the four mouse groups, suggesting that the differences in urinary VOCs between four groups are determined by the relative proportions of the compounds rather than by the presence or absence of certain compounds. Several of the compounds listed in Table 3 appear to be of exogenous origin (diet or environment). For example, 4-heptanone, 2-ethylhexanol and 2-ethylhexanoic acid are derived from plasticizers and their metabolites [17] and 1-methyl-4-(1,2,2-trimethylcyclopentyl)-benzene and 1-(1,1-dimethylethyl)-2-methyl-1,3-propanediyl 2-methylpropanoate are similar to volatile constituents from painted wallboard [18]. Several terpenes (e.g. thujopsene) are detected in mouse bedding materials (unpublished data) or may be their metabolites.


Genetically-based olfactory signatures persist despite dietary variation.

Kwak J, Willse A, Matsumura K, Curran Opiekun M, Yi W, Preti G, Yamazaki K, Beauchamp GK - PLoS ONE (2008)

Typical total ion chromatograms from the urinary volatiles extracted from four mouse groups.One representative chromatogram each from B6 mice fed Diet L, B6 mice fed Diet S, B6-H2K mice fed Diet L and B6-H2K mice fed Diet S is shown here. Prominent compound peaks include 2-acetyl-1-pyrroline (11.99 min), beta-farnesene (19.00 min), alpha-farnesene (20.63 min), and the mouse pheromones 2,3-dehydro-exo-brevicomin (13.62 min) and 2-sec-butyl-4,5-dihydrothiazole (14.93 min).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2571990&req=5

pone-0003591-g001: Typical total ion chromatograms from the urinary volatiles extracted from four mouse groups.One representative chromatogram each from B6 mice fed Diet L, B6 mice fed Diet S, B6-H2K mice fed Diet L and B6-H2K mice fed Diet S is shown here. Prominent compound peaks include 2-acetyl-1-pyrroline (11.99 min), beta-farnesene (19.00 min), alpha-farnesene (20.63 min), and the mouse pheromones 2,3-dehydro-exo-brevicomin (13.62 min) and 2-sec-butyl-4,5-dihydrothiazole (14.93 min).
Mentions: Figure 1 shows four typical total ion chromatograms (TICs) from analyses of urinary VOCs extracted by SPME from the four mouse groups (C57BL/6J (B6) Diet L, B6 Diet S, C57BL/6J-H2k (B6-H2k) Diet L, and B6-H2k Diet S). Statistical analysis of the GC/MS data collected from the 37 individual mice was performed to identify differentially-expressed compounds, many of which might co-elute with other peaks. Over 100 distinct chromatographic components were detected and we were able to identify 25 of them and another 24 compounds were tentatively identified, as seen in Table 3. Separate analyses were performed using the full profile of chromatographic components and the 49 identified components, with the same general conclusions. Unless otherwise stated, reported results are based on analysis of the 49 identified compounds so that conclusions could be attributed to known compounds, and to remove any concern that reported differences are due to instrumental artifacts or contamination. All compounds were present in each of the four mouse groups, suggesting that the differences in urinary VOCs between four groups are determined by the relative proportions of the compounds rather than by the presence or absence of certain compounds. Several of the compounds listed in Table 3 appear to be of exogenous origin (diet or environment). For example, 4-heptanone, 2-ethylhexanol and 2-ethylhexanoic acid are derived from plasticizers and their metabolites [17] and 1-methyl-4-(1,2,2-trimethylcyclopentyl)-benzene and 1-(1,1-dimethylethyl)-2-methyl-1,3-propanediyl 2-methylpropanoate are similar to volatile constituents from painted wallboard [18]. Several terpenes (e.g. thujopsene) are detected in mouse bedding materials (unpublished data) or may be their metabolites.

Bottom Line: Chemical analyses of urinary volatile organic compounds (VOCs) extracted by solid phase microextraction (SPME) and analyzed by gas chromatography/mass spectrometry (GC/MS) are consistent with this inference.Although diet influenced VOC variation more than MHC, with algorithmic training (supervised classification) MHC types could be accurately discriminated across different diets.Thus, although there are clear diet effects on urinary volatile profiles, they do not obscure MHC effects.

View Article: PubMed Central - PubMed

Affiliation: Monell Chemical Senses Center, Philadelphia, Pennsylvania, USA.

ABSTRACT
Individual mice have a unique odor, or odortype, that facilitates individual recognition. Odortypes, like other phenotypes, can be influenced by genetic and environmental variation. The genetic influence derives in part from genes of the major histocompatibility complex (MHC). A major environmental influence is diet, which could obscure the genetic contribution to odortype. Because odortype stability is a prerequisite for individual recognition under normal behavioral conditions, we investigated whether MHC-determined urinary odortypes of inbred mice can be identified in the face of large diet-induced variation. Mice trained to discriminate urines from panels of mice that differed both in diet and MHC type found the diet odor more salient in generalization trials. Nevertheless, when mice were trained to discriminate mice with only MHC differences (but on the same diet), they recognized the MHC difference when tested with urines from mice on a different diet. This indicates that MHC odor profiles remain despite large dietary variation. Chemical analyses of urinary volatile organic compounds (VOCs) extracted by solid phase microextraction (SPME) and analyzed by gas chromatography/mass spectrometry (GC/MS) are consistent with this inference. Although diet influenced VOC variation more than MHC, with algorithmic training (supervised classification) MHC types could be accurately discriminated across different diets. Thus, although there are clear diet effects on urinary volatile profiles, they do not obscure MHC effects.

Show MeSH